Organotellurium(IV) compounds containing symmetric imidobis(diphenylphosphinechalcogenide) ligands

The following compounds [C4H8Te(Ph-2(S)PNP(S)Ph-2)(2)] (1), [C4H8TeI(Ph-2(S )PNP(S)Ph-2)] (2), [C(8)H(8)Te1(Ph-2(S)PNP(S)Ph-2)] (3), [C4H8TeI(Ph-2(Se)P NP(Se)Ph-2)] (4), and [(C4H8TeOTeC4H8)(2)(Ph-2(O)PNP(O)Ph-2)(2)][1, 13] (5) were isolated from the reaction of C4H8TeI2 or C8H8TeI2 with the appropria te M[Ph-2(X)PNP(X)Ph-2] (M= K or Na; X= O, S and Se) salt. The compounds ha ve been characterized by IR, multielemental NMR spectroscopy, positive-ion FAB mass spectrometry and elemental analysis. Compounds 1, 3, 4 and 5 were also characterized by single-crystal X-ray diffraction analysis, The sulfur and selenium ligands display an asymmetrical chelating coordination mode o n interaction with the tellurium center, while two oxygen ligands behave as bridges between two C4H8Te-O-TeC4H8 units, leading to a 16-membered ring.